Dual impact means for print hammers in high speed printers



June 30,1970 WFmk 3517;611-

DUAL IMPACT MEANS FOR PRINT HAMMERS IN HIGH SPEED; PRINTERS Filed Aug 21, 1968 I m 176.? i 4 INVENTOR v WOLFGANG PINK 1' 71/ avg wnronuavs United States Patent DUAL IMPACT MEANS FOR PRINT HAMMERS IN HIGH SPEED PRINTERS Wolfgang Fink, Munich, Germany, assignor to Siemens Aktiengesellschaft, a corporation of Germany Filed Aug. 21, 1968, Ser. No. 754,417 Claims priority, application Germany, Aug. 24, 1967, 1,549,879

Int. Cl. B41j 9/10, 9/38 US. Cl. 101-93 Claims ABSTRACT OF THE DISCLOSURE In high-speed printers using a flying printing hammer, in the time which is available for printing a character all the diflerent characters which can be printed pass each printing hammer. When the character to be printed is at the printing position, it is printed.

The printing speed is primarily determined by the number of characters available and speed of movement of the type carrier, and any increase in printing speed involves an increase inone or other or both of these factors which gives rise to an increase per unit time in the number of characters passing each printing hammer.

High-speed printers in which the printing times of the individual printing hammers are determined by a timing pattern produced by mechanical means (e.g. an impact wheel) are so set up that a point of the pattern, which may be defined by the position of a tooth on the impact wheel, is allotted to each character of a moving type carrier phase-locked to said timing pattern. 'For carrying out the printing process, a connection between said mechanical means producing said timing pattern and the printing hammer is produced for a short time by means of a suitable intermediate member, known as a coupling member.

The time which is available for establishing this connection depends upon the number of characters passing the printing hammer in unit time. To increase the printing speed it is necessary to be able to shorten the time for making the connection and it is not possible to do this indefinitely for various reasons such as those due to mechanical tolerances.

Nevertheless an object of the invention is to increase the speed of a high-speed printer using a flying printing hammer.

The invention therefore consists in a high-speed printer using flying printing hammers in which the printing times of the individual printing hammers are determined by a timing pattern produced by mechanical means wherein two interlaced timing patterns are produced by two mechanical means each of which can be connected through its individual coupling member to the common printing hammer allotted thereto.

The printing speed is thus increased since by the use of two mechanical means which produce exactly interlaced timing patterns, the interval between the timing points in the overall timing pattern is halved in comparison with a system producing only one timing pattern,

without any reduction in the time available for establishing the connection between the mechanical means and the printing hammer.

An exemplary embodiment of the invention and its mode of operation will now be described with reference to the accompanying drawing.

FIG. 1 is a diagrammatic side elevational view schematically illustrating one form in which my invention may be embodied; and

FIG. 2 is an enlarged fragmentary detail view diagrammatically illustrating the manner in which the coupling member is engaged with the impact wheel to actuate a printing hammer by rotation of the wheel.

In the embodiment illustrated in the drawing, two mechanical timing and actuating means in the form of impact wheels 1, 2 one on either side of the printing position, are suitably mounted on the frame for the printer on shafts 1 and 2 respectively to rotate in a fixed relationship relative to a rotating type carrier 25 in the directions shown by the two arrows. That is, the two impact wheels 1 and 2 are positioned on opposite sides of a printing hammer 11 and driven to rotate in opposite directions at the same rates of speed. The impact teeth of one of the wheels are staggered relative to those of the other by half a tooth when related to the co-operating coupling members 3 and 4 and provide interlaced timing pattterns as said impact wheels 1 and 2 are synchronously rotating towards each other and away from the type carrier 25.

If the individual characters on the type carrier 25 are numbered consecutively, an odd numbered character is allotted for example to each impact tooth of the wheel 1, and an even number character allotted to each impact tooth of the wheel 2 (or vice versa).

The two coupling members 3 and 4 are slidably guided between stops 5 and 7 or 6 and 8 respectively and are rectilinearly movable between said stops in their longitudinal directions and are pivotally movable about said stops upon engagement of a coupling member with an associated impact wheel. The stops 5 and 7 and 6 and 8 may be suitably supported on the frame for the printer in a manner which need not herein be shown or described, since it forms no part of the present invention. For fixing their position in longitudinal direction, the coupling members have outwardly extending projections 3a and 4a respectively, which are held against the stops 7 and 8 by means of leaf springs 9 and 10.

A common printing hammer 11 associated with both coupling members holds the ends 3b and 4b of the coupling members against the stop 14. A return spring 12 extends along a slotted portion 12 of the hammer and is seated at one end on a guide member 13 extending through the slot 12 and suitably mounted in the frame for the printer. The spring 13 is a compression spring and returns the hammer to a rest position by its stored up energy after the printing operation has been carried out.

The two armature levers 17 and 18 respectively of release magnets 23, 24 are rotatably mounted at the pivots 15 and 16 are suitably mounted on the frame for the machine and are held in their rest positions against fixed stops 21 and 22 respectively by means of compression springs 19 and 20. Movements of the armature levers are transmitted to the coupling members through the projections 30 and 40 on the coupling members.

For initiating the printing process either the release magnet 23 or the release magnet 24 is energised, depending upon whether an even number or an odd number character is to be printed. In this way, the associated armature lever is pivoted and the related coupling member rectilinearly moved to engage between the teeth of an associated impact wheel. The operating time for the magnet system is so selected that a coupling member is shifted into a tooth gap of the associated rotating impact Wheel each time the associated magnet is energized. The next arriving impact tooth now rotates the coupling member about an associated stop 7 or 8 which acts as a pivot, and thus sets in motion the printing hammer 11 for carrying out the printing. During the course of movement the armature lever and coupling member move apart, so that the spring 9 or 10 acting on the projection 3a or 4a of the coupling member. The returning hammer, can then bring the coupling member back into the rest position by the bias of the spring 13 before the armature lever has again taken up its original position by the bias of the associated compression spring 19 or 20.

As soon as the armature lever has reached its rest position and all natural oscillations of the system have abated sufiiciently, the printing action can be initiated again in the described fashion.

I claim:

1. In a high-speed printer and in combination with a rotatably movable type carrier movable through a printing cycle past a printing line,

a printing hammer extending radially of said type carrier at said printing line,

means biasing said printing hammer away from said type carrier,

means engaging said printing hammer with said type carrier including two impact members,

means driving said impact members in timed relation with respect to each other and with respect to rotatable movement of said type carrier,

two coupling means each individual to a respective impact member and each engageable with said printing hammer for successively coupling said impact members to said printing hammer in a single cycle of operation to individually operate said printing hammer against its bias.

2. A high-speed printer in accordance with claim 1,

wherein the impact members are toothed impact wheels having equally spaced teeth extending thereabout, one impact wheel being on each side of the centerline of said printing hammer and the teeth of one wheel being angularly advanced relative to the teeth of the other wheel, and individually operating said coupling means in sequence to angularly move toward the type carrier and effect successive operation of said printing hammer.

3. A high-speed printer in accordance with claim 1,

wherein the coupling means are guided for reetiliner movement toward and from said impact members and for angular movement toward said type carrier, and

wherein said impact members sequentially engage said coupling means and upon engagement therewith successively move said coupling means angularly to strike said printing hammer with said type carrier. 4. A high-speed printer in accordance with claim 3, wherein spring means bias said coupling means out of engagement with said impact members and into slidable engagement with said printing hammer along an end thereof opposite from said type carrier, and

wherein other means successively move said coupling means into engagement with said impact members to effect sequential angular movement thereof out of their rectilinear paths to strike said printing hammer with said type carrier with an impact blow.

5. The high-speed printer of claim 4,

wherein the means moving said coupling means into engagement with said impact members are electromagnetic means.

6. The high-speed printer of claim 2,

wherein said coupling means are guided for movement toward and from each other in a common plane,

wherein the means biasing said printing hammer away from said type carrier comprises a spring, biasing said printing hammer into engagement with said coupling means,

wherein spring means bias said coupling means out of engagement with said toothed wheels, and

wherein electromagnetic means successively engage said coupling means between two teeth of said impact wheels to eflect angular movement of said coupling means toward said type carrier and strike said hammer with said type carrier with an impact blow.

7. The high-speed printer of claim 2,

wherein said impact wheels are disposed one above and one below the associated printing hammer,

wherein the axes of said impact wheels are in a common plane perpendicular to the axis of the printing hammer, and

wherein engagement of said coupling means between two teeth of said impact members pivot said coupling means out of said plane to move said printing hammer to strike said type carrier with an impact blow.

8. The high-speed printer of claim 6,

wherein the coupling means are guided for longitudinal movement along said common plane,

wherein spring means bias said coupling means toward each other, and

wherein electromagnetic means move said coupling means against said spring means to engage between two teeth of an associated impact wheel.

9. A high-speed printer in accordance with claim 1,

wherein the impact members are impact wheels having a plurality of equally spaced teeth extending thereabout and driven at the same rates of speed and in timed relation with respect to the speed of said type carrier,

wherein said coupling means extend along the opposite end of said printing hammer from said type carrier and are movable therealong toward and from each other,

wherein spaced stops on opposite sides of said coupling means guide said coupling means for rectilinear movement toward and from each other,

wherein spring members bias said coupling means out of engagement with the teeth of said impact wheels, and

wherein angularly movable members move said coupling members into the space between two teeth of said toothed wheels to be successively angularly moved thereby to move said hammer to strike said type carrier with an impact.

10. The high-speed rinter of claim 9,

wherein spring means move said angularly movable members toward each other in position to be inelfective to operate said coupling means, and

wherein electromagnetic means move said angularly movable members in directions toward said impact Wheels to successively engage said coupling means in the space between two teeth of said toothed wheels.

References Cited UNITED STATES PATENTS 2,766,686 10/1956 Fomenko et al. 10193 2,893,313 7/1959 Pekar et al. 10193 3,012,499 12/1961 Amada 101111 X 3,144,821 8/1964 Drejza 101-93 3,145,650 8/1964 Wright 10193 3,255,693 6/1966 Eissfelot et al. 10193 3,386,376 6/1968 Mutz et a1. 10193 WILLIAM B. PENN, Primary Examiner 

